Check pawl for wire stitchers



June 18, 1929. G, n BAUMANN 1,718,200

CHECK PAWL FOR WIRE STITCHERS Filed Dec, 24, 1927 Patented `lune 18, 1929.

UNITED STATES 1,718,200 PATENT OFFICE.

GOTTFB'IED P. BAUMANIT, OF CHICAGO, ILLINOIS, ASSIGNOR lO IDEAL STITCI-IER 8c MANUFACTURING CO., OF CHICAGO, ILLINOIS.

CHECK PAWL FOI?, WIRE STITCIIERS.

Application filed December 24, 1927. Serial No. 242,496.

My invention relates to check pawls for wire stitchers and has to do more particularly with devices of the above character adapted to cheek a restoring or return movement of the wire being fed to the machine, although permitting movement of the wire in feeding the stitehers.

An object of my invention is to provide an improved and simplified device of the above character which is ycheap to manufacture, simple in construction, and positive in operation.

For a better understanding of my invention reference is to be had to the accompanying drawing, in which- Fig. 1 is a face view of a stitcher head,

showing my improved cheek pawl appliedr thereto;

Fig. 2 is an enlarged view of the check pawl partly in section to show the 'check pins and their operating cam with the pins moved downwardly to permit a free return movement of the wire when it is to be drawn out of the device by hand;

Fig. 3 shows the device in its normal adjustment with the check pins gripping the wire;

Fig. 4 is a cross sectional view along the line 4 4 of l? ig. 2;

F ig. 5 is a vertical sectional view along the line 5 5 of F ig. 3; and

Fig. 6 is a detail view of the check pin holding or operating collar.

Referring now more in detail to my invention as illustrated, I have shown itapplied to a well known form of stitcher having` the usual feed rollers 6 7, between the peripheral feeding faces of which the wire 8 extends to the tube 9 and then to the `cut-off, former and driver mechanism 10.

Referring now more in detail to the cheek pawl, this comprises a suitable guide and frame in the form of a tubular member 11 through which the wire 8 extends, said member 11 being supported by a bracket 12 extending forwardly from the stitcher head and in which the device is adjustably held by a set screw 13. A pair of gripping or cheek elements are supported in the tube or frame, these elements being preferably in the form of pins or rods 14- 15 positioned upon opposite sides of the wire 8 and slidably held in the transverse opening 16 extending through the tube 11 and having tapered walls so as to force the pins 14-15 into holding engagement with the wire 8 when they are moved upwardly between these tapered walls. These check pins 14 15 are supported in a collar 17- slidably mounted upon the tube or frame 11said eollar having a transverse slot 18 extending therethrough in which the pins are loosely held. In order to retain the pins in the collar, I provide a split spring ring 19 which is snapped over the collar into the annular' groove 20 where it is retained to hold the pins in the collar. i

It will thus be seen that by shifting the collar 17 along' on the tube 11, the cheek pins 14 15 due to engagement by the tapering walls of the inner slot 16, will grip and hold the wire so as to prevent upward movement thereof, although it will allow a downward feed of the wire.

In order to hold the check pins in operative engagement with the wire 8, I provide a spring 21 which encircles the tube 11 and presses the collar 17 with its cheek pins upwardly or toward the narrow end of the slot 16. Thus any feeding or downward pull on the wire 8 is readily permitted, because if there is any movement of the pins it is to free them of the wire. However, any back pull on the wire 8 immediately causes the check pins to grip the wire and prevent its return movement.

In actual operation the device is so sensitive and positive that although the wire may be freely fed forwardly, as soon as a back pull is exerted upon the wire no return movement can be detected.

Also I find that the check pawl permits a clean feed of the wire, that is, there are no scrapings from the wire as I find from other check pawls and which scrapings drop down into the mechanism and unless frequently cleaned out interfere with the proper operation of the stitcher.

I also find that the device works most positively from the smallest size wire used to the largest limits of the device and always with a most positive operation. Also it operates j ust as effectively with various kinds of wire. whether flat or round.

In the use of the device, and assuming there is no wire in it and that the check pins have been moved upwardly to their limit by reason of the spring 21, to apply the wire it is simply inserted through the upper end of the opening 11 in the tube and by pushing it in the tubeit "will move down between the check pins, or if it will not freely enter between the pins the collar 17 is grasped between the lingers and moved downwardly sufliciently to bring the check pins to a point in the tapered slot where there will be suiiicient clearance to allow the wire to enter. By releasing the collar 17 it is moved upwardly by the spring 21 to grip the wire and permit the feeding operation as described.

What I claim as new and desire to secure by United States Letters Patent is:

1. A check pawl for wire stitchers including a wire conducting tubular member' having a transverse opening therethrough with longitudinally tapered walls, a pair of wire gripping pins extending through the opening, and a spring pressed collar around the tubular member for normally pressing the pins against the tapered walls to grip the wire to check the return movement of the wire but permit feeding movement thereof between the pins.

2. A check pawl for wire strctchers including a wire conducting member having a wire conducting opening extending longitudinally therethrough and a transverse opening with longitudinally tapered walls, opposed. gripping pins extending through the opening, and 'spring means for normally pressing the pins against the tapered walls to check return movement of the wire but permit feeding movement thereof.

3. A check pawl for wire stitchers including a wire conducting member having a wire conducting opening extending longitudinally therethrough and a transverse opening with longitudinally tapered walls, opposed gripping pins extending through the opening,

and means supporting the pins for yieldingly holding them against the tapered walls to permit movement in one direction to release the wire but to prevent movement in the other direction to lock the wire.

ln witness whereof, l hereunto subscribe my name this 28th day of February, 1927. GTTFRIED l. BAUMANN. 

